Modification of genomic DNA is of immense importance for basic and applied research. Genomic modifications have the potential to elucidate and in some cases to cure the causes of disease and to provide desirable traits in the cells and/or individuals comprising said modifications. Genomic modification may include, for example, modification of plant, animal, fungal, and/or prokaryotic genomic modification. The most common methods for modifying genomic DNA tend to modify the DNA at random sites within the genome, but recent discoveries have enabled site-specific genomic modification. Such technologies rely on the creation of a DSB at the desired site. This DSB causes the recruitment of the host cell's native DNA-repair machinery to the DSB. The DNA-repair machinery may be harnessed to insert heterologous DNA at a pre-determined site, to delete native genomic DNA, or to produce point mutations, insertions, or deletions at a desired site. Of particular interest for site-specific genomic modifications are Clustered, Regularly Interspersed Short Palindromic Repeat (CRISPR) nucleases. CRISPR nucleases use a guide molecule, often a guide RNA molecule, that interacts with the nuclease and base pairs with the targeted DNA, allowing the nuclease to produce a double-stranded break (DSB) at the desired site. The production of DSBs requires the presence of a protospacer-adjacent motif (PAM) sequence; following recognition of the PAM sequence, the CRISPR nuclease is able to produce the desired DSB. Cms1 CRISPR nucleases are a class of CRISPR nucleases that have certain desirable properties relative to other CRISPR nucleases such as Cas9 nucleases.
One area in which genomic modification is practiced is in the modification of plant genomic DNA. Modification of plant genomic DNA is of immense importance to both basic and applied plant research. Transgenic plants with stably modified genomic DNA can have new traits such as herbicide tolerance, insect resistance, and/or accumulation of valuable proteins including pharmaceutical proteins and industrial enzymes imparted to them. The expression of native plant genes may be up- or down-regulated or otherwise altered (e.g., by changing the tissue(s) in which native plant genes are expressed), their expression may be abolished entirely, DNA sequences may be altered (e.g., through point mutations, insertions, or deletions), or new non-native genes may be inserted into a plant genome to impart new traits to the plant.